[PATCH 2/8] KVM: Simplify is_long_mode()

From: Avi Kivity
Date: Thu Dec 28 2006 - 05:09:37 EST


Instead of doing tricky stuff with the arch dependent virtualization registers,
take a peek at the guest's efer.

This simlifies some code, and fixes some confusion in the mmu branch.

Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>

Index: linux-2.6/drivers/kvm/mmu.c
===================================================================
--- linux-2.6.orig/drivers/kvm/mmu.c
+++ linux-2.6/drivers/kvm/mmu.c
@@ -578,7 +578,7 @@ static int init_kvm_mmu(struct kvm_vcpu

if (!is_paging(vcpu))
return nonpaging_init_context(vcpu);
- else if (kvm_arch_ops->is_long_mode(vcpu))
+ else if (is_long_mode(vcpu))
return paging64_init_context(vcpu);
else if (is_pae(vcpu))
return paging32E_init_context(vcpu);
Index: linux-2.6/drivers/kvm/kvm_main.c
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm_main.c
+++ linux-2.6/drivers/kvm/kvm_main.c
@@ -398,7 +398,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsi
return;
}

- if (kvm_arch_ops->is_long_mode(vcpu)) {
+ if (is_long_mode(vcpu)) {
if (!(cr4 & CR4_PAE_MASK)) {
printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
"in long mode\n");
@@ -425,7 +425,7 @@ EXPORT_SYMBOL_GPL(set_cr4);

void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
- if (kvm_arch_ops->is_long_mode(vcpu)) {
+ if (is_long_mode(vcpu)) {
if ( cr3 & CR3_L_MODE_RESEVED_BITS) {
printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
inject_gp(vcpu);
Index: linux-2.6/drivers/kvm/kvm.h
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm.h
+++ linux-2.6/drivers/kvm/kvm.h
@@ -278,7 +278,6 @@ struct kvm_arch_ops {
struct kvm_segment *var, int seg);
void (*set_segment)(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg);
- int (*is_long_mode)(struct kvm_vcpu *vcpu);
void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);
void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
void (*set_cr0_no_modeswitch)(struct kvm_vcpu *vcpu,
@@ -403,6 +402,15 @@ static inline struct page *_gfn_to_page(
return (slot) ? slot->phys_mem[gfn - slot->base_gfn] : NULL;
}

+static inline int is_long_mode(struct kvm_vcpu *vcpu)
+{
+#ifdef CONFIG_X86_64
+ return vcpu->shadow_efer & EFER_LME;
+#else
+ return 0;
+#endif
+}
+
static inline int is_pae(struct kvm_vcpu *vcpu)
{
return vcpu->cr4 & CR4_PAE_MASK;
Index: linux-2.6/drivers/kvm/svm.c
===================================================================
--- linux-2.6.orig/drivers/kvm/svm.c
+++ linux-2.6/drivers/kvm/svm.c
@@ -166,11 +166,6 @@ static inline void write_dr7(unsigned lo
asm volatile ("mov %0, %%dr7" :: "r" (val));
}

-static inline int svm_is_long_mode(struct kvm_vcpu *vcpu)
-{
- return vcpu->svm->vmcb->save.efer & KVM_EFER_LMA;
-}
-
static inline void force_new_asid(struct kvm_vcpu *vcpu)
{
vcpu->svm->asid_generation--;
@@ -1609,7 +1604,6 @@ static struct kvm_arch_ops svm_arch_ops
.get_segment_base = svm_get_segment_base,
.get_segment = svm_get_segment,
.set_segment = svm_set_segment,
- .is_long_mode = svm_is_long_mode,
.get_cs_db_l_bits = svm_get_cs_db_l_bits,
.set_cr0 = svm_set_cr0,
.set_cr0_no_modeswitch = svm_set_cr0,
Index: linux-2.6/drivers/kvm/paging_tmpl.h
===================================================================
--- linux-2.6.orig/drivers/kvm/paging_tmpl.h
+++ linux-2.6/drivers/kvm/paging_tmpl.h
@@ -68,7 +68,7 @@ static void FNAME(init_walker)(struct gu
hpa = safe_gpa_to_hpa(vcpu, vcpu->cr3 & PT64_BASE_ADDR_MASK);
walker->table = kmap_atomic(pfn_to_page(hpa >> PAGE_SHIFT), KM_USER0);

- ASSERT((!kvm_arch_ops->is_long_mode(vcpu) && is_pae(vcpu)) ||
+ ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
(vcpu->cr3 & ~(PAGE_MASK | CR3_FLAGS_MASK)) == 0);

walker->table = (pt_element_t *)( (unsigned long)walker->table |
@@ -131,7 +131,7 @@ static pt_element_t *FNAME(fetch_guest)(
(walker->table[index] & PT_PAGE_SIZE_MASK) &&
(PTTYPE == 64 || is_pse(vcpu))))
return &walker->table[index];
- if (walker->level != 3 || kvm_arch_ops->is_long_mode(vcpu))
+ if (walker->level != 3 || is_long_mode(vcpu))
walker->inherited_ar &= walker->table[index];
paddr = safe_gpa_to_hpa(vcpu, walker->table[index] & PT_BASE_ADDR_MASK);
kunmap_atomic(walker->table, KM_USER0);
Index: linux-2.6/drivers/kvm/vmx.c
===================================================================
--- linux-2.6.orig/drivers/kvm/vmx.c
+++ linux-2.6/drivers/kvm/vmx.c
@@ -900,11 +900,6 @@ static void vmx_set_segment(struct kvm_v
vmcs_write32(sf->ar_bytes, ar);
}

-static int vmx_is_long_mode(struct kvm_vcpu *vcpu)
-{
- return vmcs_read32(VM_ENTRY_CONTROLS) & VM_ENTRY_CONTROLS_IA32E_MASK;
-}
-
static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
{
u32 ar = vmcs_read32(GUEST_CS_AR_BYTES);
@@ -1975,7 +1970,6 @@ static struct kvm_arch_ops vmx_arch_ops
.get_segment_base = vmx_get_segment_base,
.get_segment = vmx_get_segment,
.set_segment = vmx_set_segment,
- .is_long_mode = vmx_is_long_mode,
.get_cs_db_l_bits = vmx_get_cs_db_l_bits,
.set_cr0 = vmx_set_cr0,
.set_cr0_no_modeswitch = vmx_set_cr0_no_modeswitch,
-
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